Project description:rs11-03_agro transcriptomic comparison of tumoric tissues induced by different c58 agrobacterium lines What are the functions and the regulatory pathways of the bacterial quorum-sensing system in the context of Agrobacterium/Arabidopsis interactions? Arabidopsis WT Col0 plants were grown in greenhouse till stage 1.03-1.04 (growth conditions 1). They were then confined in short day conditions and at 22°C (growth conditions 2). At stage 5.10 plants were wounded at the base of the stem and part of them were inoculated with 3 different C58 Agrobacterium strains (WT, accR or traI). Eighteen days post inoculation, wounded but non-infected tissues (control) as well as tumoric tissues were collected and processed for RNA extraction. 21 dye-swap

Project description:The pathogen Agrobacterium tumefaciens infects a broad range of plants, introducing the T-DNA into their genome. Contrary to all known bacterial phyto-pathogens, Agrobacterium lacks the hypersensitive response-inducing HRP genes although it introduces numerous proteins into the plant cell through a type IV secretion system. To understand the timing and extent of the plant transcriptional response to this unusual pathogen, we used an Arabidopsis 26-thousand gene oligonucleotide microarray. We inoculated Arabidopsis cell cultures with an oncogenic strain of Agrobacterium and analyzed four biological replicates to identify two robust sets of regulated genes, one induced and the other suppressed. In both cases, the response was distinct at 48 hours after infection, but not at 24 hours or earlier. The induced set includes genes encoding known defense proteins, the repressed set is enriched with genes characteristic of cell proliferation even though a growth arrest was not visible in the inoculated cultures. The analysis of the repressed genes revealed that the conserved upstream regulatory elements Frankiebox (a.k.a. “site II”) and Telobox are associated with the suppression of gene expression. The regulated gene sets should be useful in dissecting the signaling pathways in this plant-pathogen interaction. Keywords: Time-course of Agrobacterium infection Overall design: Time-course of Agrobacterium-inoculated Arabidopsis cell cultures. Four biological replicates of mock- and Agrobacterium-inoculated samples collected at 4h, 12h, 24h and 48h after inoculation were compared to a reference RNA in a oligonucleotide array.

Project description:This research focuses on the design, manufacturing and validation of a new Agrobacterium tumefaciens C58 whole-genome tiling microarray platform for novel RNA transcript discovery. A whole-genome tiling microarray allows both annotated genes as well as previously unknown RNA transcripts to be detected and quantified at once. The Agrobacterium tumefaciens C58 genome is re-acquired with next-generation sequencing and then used to design the tilinlg microarray with the thermodynamic analysis program Picky. Validations are performed by subjecting Agrobacterium tumefaciens C58 under various growth conditions and then using the tling microarrays to verify expected gene expression patterns. Overall design: Agrobacterium tumefaciens C58 was grown under 10 different conditions: a standard condition and 9 stressful conditions. 2 replications were measured for each condition.